feat: VivesPOS landing on Winter CMS 1.2 — theme + plugin + Dockerfile

- Base: wintercms/winter branch 1.2 (full framework)
- Theme vivespos: Canvas 7 + Bootstrap 5 CDN, custom CSS
- Layout: deferred GTM/GA4 tracking, JSON-LD SoftwareApplication
- Partials: hero (offline-first), features, modes (offline/nube toggle),
  screenshots, pricing (3 planes), comparison, FAQ, CTA
- Plugin VivesPOS.Site with ContactForm
- Dockerfile: PHP 8.2 Apache, port 80, healthcheck
- Added winter/wn-pages, blog, sitemap, seo plugins
- Active theme set to vivespos

.devcontainer/local-features/bootstrap-winter/devcontainer-feature.json

@@ -0,0 +1,6 @@
+{
+    "id": "bootstrap-winter",
+    "name": "Bootstrap Winter",
+    "description": "Bootstrap and configure Winter CMS automatically for development on Winter itself",
+    "postCreateCommand": "sh ./.devcontainer/local-features/bootstrap-winter/bootstrap.sh"
+}